Fig. 3.

Distribution of AP-EXO_R&L&Sin vivo and in vitro. (a) Timeline of surgical interventions for experiments presented in (a–f) and Supplementary Figs. 2b–c. Spinal cord contused C57BL/6 mice received a single intravenous injection of DiR-labeled AP-EXO or AP-EXO_R&L&S (30 μg). After 2 h, the mice were sacrificed and the fluorescence of different tissues was imaged. Blank designated as the mice injected with PBS. AP-EXO designated as the mice injected with DiR-labeled AP-EXO. AP-EXO_R&L&S designated as the mice injected with RVG-CP05, ILP-CP05 and ISP-CP05 loaded AP-EXO. (b) Distribution of fluorescence intensity in body-wide tissues. (c) Quantitative analysis of fluorescence intensity in body-wide tissues. (n = 3, *p < 0.05, Brain, one-way ANOVA on ranks post Tukey Test. Spinal cord, one-way ANOVA post Student-Newman-Keuls test). (d) Representative images of DiR-labeled AP-EXO in injured region after AP-EXO or AP-EXO_R&L&S injected. Scale bar: 200 μm. (e) Quantitative comparison of the ratio of the DiR-labeled AP-EXO distributed area to injured area across 3 groups. (n = 3, **p < 0.001, one-way ANOVA post Student-Newman-Keuls test). (f) Representative images showing the colocalization of DiR-labeled AP-EXO with NF200-labeled neurons. Scale bar: 200 μm, inset: 100 μm. (g–j) Spinal cord contused C57BL/6 mice received a single intravenous injection of AP-EXO_R&L&S (DiR-labeled AP-EXO 30 μg incubated with the same amount of rhodamine-labeled ISP-CP05, FAM-labeled ILP-CP05 and Alexa Fluor 405-labeled RVG-CP05) at determined time point. The mice were sacrificed at specified time point of 2 h, 1 d, 3 d, 7 d post injection and the fluorescence of different tissues was imaged. g, distribution for fluorescence intensity of AP-EXO in the injured spinal cord. h, quantitative analysis of fluorescence intensity at different time-points. Scale bar: 500 μm, inset: 100 μm. i, representative images for ISP-CP05, ILP-CP05, RVG-CP05 and AP-EXO localization in the injury sites. j, quantitative analysis of colocalization of ISP-CP05, ILP-CP05 and RVG-CP05 to AP-EXO. (k) Representative images showing the colocalization of pkh-26 labeled AP-EXO with ALDH1L1-positive primary astrocytes and Tuj 1- positive primary neurons after incubated with AP-EXO or AP-EXO_R&L&Sin vitro. Scale bar: 20 μm. (l) Quantitative comparison of AP-EXO (pkh26) positive astrocytes and neurons in 2 groups of AP-EXO or AP-EXO_R&L&S. (n = 5, *p < 0.05, **p < 0.001, two tailed t-test). Representative images of Fig. 2d and f and Supplementary Fig. 2c were from the same tissue.